Flexible Sigmoidoscopy Screening Reduces Mortality

MONDAY, Aug. 21, 2017 (HealthDay News) -- Screening with flexible sigmoidoscopy reduces all-cause mortality, according to a research letter published online Aug. 22 in the Annals of Internal Medicine.

Andrew W. Swartz, M.D., from the Yukon-Kuskokwim Delta Regional Hospital in Bethel, Alaska, and colleagues examined the results of the Norwegian Colorectal Cancer Prevention (NORCCAP) study for a Simpson paradox and repeat meta-analysis of all-cause mortality outcomes for screening flexible sigmoidoscopy. Data were extracted from four studies, and meta-analysis was performed.

The researchers found that the relative risk for all-cause mortality favoring screening was 0.96 (95 percent confidence interval [CI], 0.87 to 1.06) in the younger cohort (age 50 to 54 years) of the NORCCAP study, while the relative risk for the older cohort (ages 55 to 64 years) was 0.98 (95 percent CI, 0.94 to 1.03). The relative risk for the combined summary estimate of these cohorts was 0.98 (95 percent CI, 0.94 to 1.02). When the cohorts were aggregated into a single group, the relative risk was 1.07 (95 percent CI, 1.02 to 1.12), favoring no screening. Using the individual NORCCAP study cohorts, flexible sigmoidoscopy reduced all-cause mortality (relative risk, 0.975; 95 percent CI, 0.959 to 0.992; P = 0.004) at 11 to 12 years. The absolute risk reduction was 3.0 deaths per 1,000 persons invited to screening after 11.5 years of follow-up.